As shown in FIG. 10, a ladder-type surface acoustic wave filter 101 includes piezoelectric substrate 120; first series resonator 103 which is one of series resonators formed on piezoelectric substrate 120 and has the lowest resonance frequency among the series resonators; and dielectric film 106 formed on piezoelectric substrate 120 so as to cover resonator 103. Filter 101 further includes second series resonator 105 formed on piezoelectric substrate 120 and having a resonance frequency higher than that of resonator 103; and dielectric film 107 formed on piezoelectric substrate 120 so as to cover resonator 105.
In this configuration, film thickness Ha of dielectric film 106 is equal to film thickness Hb of dielectric film 107.